I just read this here: http://www.atpworldtour.com/rankings/rankings-faq.aspx#requirementsQ. What are the requirements and rules for player participation for an ATP World Tour 500 tournament?A. Top 30 players (based on 2012 year-end Emirates ATP Rankings) must play a minimum of four 500 level tournaments during the calendar year, including at least one event following the US Open (Monte Carlo Masters 1000 event will count towards the minimum of four and all penalties apply):-- A 0-pointer for each event less than four played.-- A 0-pointer for withdrawing from any 500 tournament after the acceptance list is out.-- A 0-pointer for not playing at least one event after the US Open.-- A 0-pointer can be appealed by a player to the same tribunal formed to hear 1000 suspension appeals.-- No suspensions or fines (including no withdrawal and late withdrawal fines).

I don't completely understand what the penalties are, so after Monaco, I would guess Andy will play Tokyo, Valencia. But will he get fined or a points cut if he does not play Citi?

Can he even count the points from this? As well as the bit Wildster quoted above, ATP site says

In November 2011, the ATP Board passed a rule to allow more flexibility in which tournaments count toward the ranking of a commitment player in 2012 and 2013.

Commitment players (top 30 in 2012 year-end ranking) can count their best six (6) results from ATP World Tour 500, ATP World Tour 250 and other events (Challengers, Futures, Davis Cup, Olympics) toward their ranking. To count their best six (6), players must have fulfilled their commitment to 500 events - 4 total per year (at least 1 after the US Open).

So if he hasn't committed to 4 x 500 events, can he count more than 2 x 250? Having won Brisbane and Queens, he can't score more!

There are only 3 more opportunities for 500s this year: Washington, Beijing/Tokyo, Valencia/Basel. Presumably he gets a 0 point penalty for any of these he doesn't play, as he's only done MC? (Nadal has 0 points for Beijing and Valencia last year as he'd only played MC and Barcelona)